You'll pay: Efficient cord wood stoves start about $1,700; pellet stoves are $3,000 to $4,000.
You'll save: 30 to 50 percent on heating.
Why do it now? Heating with pellets or cord wood is cheaper than using oil or electricity at current rates. (Annual fuel costs are about $300 to $600 for a stove used as a primary heat source, roughly on par with natural gas.) Some models require a new chimney, which can add a few thousand bucks to your initial cost, says Scheckel.
What to look for: Qualified stoves, like Hearthstone's cord wood models, are pricier than the old-school pot-bellied kind but are much more efficient. Opt for one that uses fuel that's readily available where you live.
Bottom line: A stove won't pay off if you heat with natural gas. But if you use oil or electricity, you'll save by supplementing with or switching to a stove or insert.